Al Jazeera accesses 400,000 secret US military documents, which reveal the inside story of the Iraq war.

In the biggest leak of military secrets in history, WikiLeaks, the whistleblower website, has released 400,000 secret US files detailing every aspect of the war in Iraq, copies of which have been obtained by Al Jazeera.

The sheer magnitude of data contained in the secret files reveals a graphic narrative of the war that goes far beyond any information about the conflict ever released into the public domain.

What has been uncovered often contradicts the official narrative of the conflict. For example, the leaked data shows that the US has been keeping records of Iraqi deaths and injuries throughout the war, despite public statements to the contrary.

The latest cache of files pertains to a period of six years – from January 1, 2004, to December 31, 2009 – and shows that 109,000 people died during this time. Of those, a staggering 66,081 – two-thirds of the total – were civilians.

The figures are much higher than previously estimated and they will inevitably lead to an upward revision of the overall death toll of the conflict.

As a result of the information contained in the war logs, the Iraq Body Count (IBC) – an organisation that kept records of the number of people killed – is about to raise its death toll estimates by 15,000: to 122,000 from 107,000.

The new material throws light on the day-to-day horrors of the war. The military calls them SIGACTs – significant action reports – ground-level summaries of the events that punctuated the conflict: raids, searches, roadside bombings, arrests, and more. All of them are classified “secret”.

The reports reveal how torture was rampant and how ordinary civilians bore the brunt of the conflict.

The files record horrifying tales: of pregnant women being shot dead at checkpoints, of priests kidnapped and murdered, of Iraqi prison guards using electric drills to force their prisoners to confess.

Equally disturbing is the response of the military to the civilian deaths caused by its troops. Excessive use of force was routinely not investigated and the guilty were rarely brought to book.

We understand that lives could be put at risk with the publication of such sensitive data, so you'll notice we've redacted almost all the names that appear in these cables – the exception being very well-known figures, people like Iraqi prime minister Nouri al-Maliki. Our media partners have done the same.

But working alongside the New York Times, The Guardian, Der Spiegel, and the UK's Channel 4 TV, Al Jazeera is clear that releasing the Iraq files – despite their secret nature – is vital to the public interest.